Against the backdrop of tightening global environmental regulations, iron and steel enterprises worldwide are under growing pressure to achieve stable ultra-low flue gas emissions while controlling comprehensive environmental operation costs. Hot blast stoves, CDQ (Coke Dry Quenching) systems and sintering production lines present particularly challenging treatment conditions: fluctuating flue gas temperature, variable gas volume, and complex acidic pollutant components including SO2, SO3, HCl and HF. Conventional wet desulfurization and SDS sodium bicarbonate dry processes often fall short in balancing treatment efficiency, investment cost and long-term operational expenditure.
Tianjin Huineng Environmental Protection Technology Co., Ltd. is a national high-tech enterprise specializing in the R&D, production and application of ultra-fine high specific surface calcium hydroxide desulfurizer, alongside integrated flue gas treatment EPC contracting and industrial waste heat recovery turnkey projects. With independent intellectual property rights and a mature HNPS dry calcium injection process, Huineng has established long-term cooperative relationships with leading steel groups including Baowu, Shougang and Ansteel, providing reliable environmental solutions for large-scale metallurgical facilities.
Core Product: Ultra-Fine High Specific Surface Calcium Hydroxide Desulfurizer
The core product of Huineng is an ultra-fine high specific surface calcium hydroxide desulfurizer customized for industrial flue gas treatment. With available Ca(OH)2 content above 92%, specific surface area exceeding 42m2/g, and full passing through 325-mesh sieve, the product demonstrates significantly higher reaction activity than ordinary industrial lime powder. The ultra-fine particle size ensures rapid and uniform dispersion in turbulent flue gas, maximizing the contact area between calcium-based active components and acidic pollutants, thereby achieving high desulfurization efficiency at lower reagent dosage.
A key technical advantage of Huineng's desulfurizer lies in its excellent low-temperature adaptability. The effective reaction temperature range covers 30℃ to 380℃, perfectly matching the wide temperature fluctuation characteristics of hot blast stove flue gas. Unlike SDS sodium bicarbonate desulfurization which requires flue gas temperature above 150℃ for efficient activation, Huineng's calcium-based desulfurizer maintains stable reaction performance even in low-temperature flue gas sections, eliminating the need for additional flue gas heating equipment and associated energy consumption.
HNPS Dry Calcium Injection Process: Principle and Workflow
The HNPS dry desulfurization system developed by Huineng adopts a fully enclosed pneumatic powder injection design. The process flow consists of five key stages: sealed material storage and feeding, variable-frequency quantitative pneumatic injection, preliminary gas-phase reaction in the main flue duct, deep secondary desulfurization in the baghouse filter cake layer, and sealed ash discharge with optional recycling for resource utilization.
During operation, the ultra-fine desulfurization powder is uniformly injected into the main flue through a high-pressure pneumatic conveying device. The powder disperses instantly in the turbulent flue gas flow and undergoes preliminary gas-solid reaction, removing the majority of SO2, SO3, HCl and HF. The mixed flue gas then enters the baghouse dust collector, where calcium hydroxide dust forms a 0.8–1.2mm reactive filter cake layer on the surface of filter bags. Unreacted active calcium components within this filter cake continuously adsorb residual sulfides as flue gas passes through, realizing secondary advanced desulfurization and ensuring stable outlet emission below ultra-low limits.
The desulfurization ash collected by the dust collector contains residual active calcium components, which can be re-injected into the flue through circulating pneumatic pipelines to further improve reagent utilization rate and reduce unit consumption. Spent waste residue is discharged into a finished ash silo in a sealed manner for unified external sales and resource utilization as raw materials for cement production and sintering batching.
Economic and Environmental Advantages Over Traditional Processes
Compared with the SDS sodium bicarbonate desulfurization process, Huineng's calcium-based dry solution delivers comprehensive cost reduction exceeding 30% in total operating expenditure. The raw material cost of calcium hydroxide desulfurizer is substantially lower than that of food-grade sodium bicarbonate. Additionally, the elimination of supporting grinding equipment and high-temperature flue gas heating devices significantly reduces equipment investment, energy consumption and maintenance expenses.
From an environmental perspective, the full-dry process requires no process water throughout the system, achieving zero wastewater discharge. This avoids common problems associated with wet desulfurization, such as white smoke plume emission, equipment corrosion, gypsum scaling and wastewater treatment costs. The by-product desulfurization ash is classified as general industrial solid waste, in stark contrast to the sodium sulfate residues generated by the SDS process which are categorized as hazardous waste requiring specialized and costly disposal.
The strong adaptability of the HNPS system to variable working conditions is another critical advantage for steel enterprises. During hot blast stove switching operations or sharp changes in flue gas temperature and volume, the system maintains stable emission indicators without excessive fluctuation, satisfying the demand for non-stop continuous production of large-scale blast furnaces. The excellent powder fluidity of Huineng's desulfurizer also ensures smooth pneumatic conveying without pipe blockage, making it highly suitable for intermittent variable-load powder injection scenarios.
Industrial Verification: Baowu Shaogang 4500m³ Blast Furnace Hot Blast Stove Project
The technical maturity and operational stability of Huineng's solution have been fully verified through large-scale industrial application. The 4500m³ blast furnace hot blast stove desulfurization project of Baowu Shaogang represents a landmark implementation case. Following project commissioning, long-term operation data demonstrates that the outlet SO2 concentration is stably controlled within 15–35mg/Nm3, superior to the national ultra-low emission limit of 50mg/Nm3, with overall desulfurization efficiency exceeding 92%.
The outlet dust concentration is maintained below 8mg/Nm3, while hydrogen chloride and hydrogen fluoride in the flue gas are simultaneously removed through collaborative adsorption. All emission indicators fully meet the internal environmental management standards of Baowu Group. The successful operation of this project confirms that the combination of Huineng's ultra-fine high specific surface calcium hydroxide desulfurizer and the HNPS dry process is an optimal solution for flue gas desulfurization under low-temperature and variable working conditions of hot blast stoves for large-scale iron and steel blast furnaces.
Full-Chain Manufacturer Service and Technical Support
As a designated desulfurizer supplier within the Baowu system and a long-term partner of major steel groups, Tianjin Huineng provides integrated full-chain services covering reagent production, process design, equipment matching, on-site commissioning and long-term material supply. The company maintains a dedicated on-site technical operation and maintenance team to guarantee stable continuous production for customers, with rapid response to any operational adjustments or technical issues.
For customers seeking to optimize existing desulfurization facilities or construct new flue gas treatment systems, Huineng offers professional working condition assessment and detailed cost comparison schemes based on actual flue gas parameters. The technical team evaluates factors including flue gas temperature range, gas volume, inlet pollutant concentration, existing dust collector configuration and site layout, to develop customized treatment plans that maximize cost-effectiveness while ensuring compliance with local emission standards.
With continuous investment in R&D and growing industrial application experience, Huineng's calcium-based dry desulfurization technology has been replicated and applied in batches across hot blast stove, CDQ, sintering and boiler projects of multiple steel plants affiliated to Baowu and other leading metallurgical groups. The solution delivers triple benefits of environmental compliance, cost reduction and efficiency improvement, and solid waste resource recovery, making it an increasingly preferred choice for steel and coking enterprises pursuing sustainable and economical flue gas treatment.
Whether you require bulk supply of high specific surface calcium hydroxide desulfurizer, technical transformation of existing desulfurization systems, or EPC general contracting of complete flue gas treatment and waste heat recovery projects, Huineng is ready to provide professional, reliable and cost-effective solutions tailored to your specific production conditions. Contact our team today to schedule a working condition evaluation and explore how our dry desulfurization technology can reduce your environmental operation costs while ensuring stable ultra-low emissions.
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Tianjin Huineng Environmental Protection Technology Co., Ltd.